Calcium Hardness

Calcium hardness is a measure of the dissolved calcium salts in water.

The proper range of calcium hardness varies depending on the pool surface, but it should generally be maintained between 180 and 250 ppm. For gunite, concrete or plaster pools, the calcium hardness should be maintained on the higher end, closer to 250 ppm.

If calcium hardness is very low then water may leach calcium from pool walls causing pitting of the plaster surface.

Very high calcium hardness may contribute to scale formation and clouding of the water.

To raise calcium hardness, add Robelle Calcium Plus.